Question

if tan theta equals 1by root5 and theta lies in the first quadrant, the value of cos theta is?​

Answer 1

Answer:

$tanx= 1/√5</p><p></p><p>sec²x-tan²x= 1</p><p></p><p>sec²x= 1+ tan²x</p><p></p><p>sec²x= 1+ (1/√5)²</p><p></p><p>sec²x= 1+ 1/5</p><p></p><p>sec²x= 6/5</p><p></p><p>secx= √(6/5)</p><p></p><p>cosx= √(5/6)</p><p></p><p>$